1. Field of the Invention
The invention relates to catheters for intravenous applications.
2. Description of the Related Art
Each year, the number of individuals who are infected with Human Immuno-deficiency Virus (HIV), Hepatitis B (HPV), and other dangerous diseases is increasing. Currently, the Center for Disease Control (CDC) estimates that from 1.5-2 million people in the United States are infected with HIV. Many of these HIV cases are undiagnosed, which makes anyone who comes in contact with the infected person's body fluids vulnerable to HIV infection as well. Nurses and doctors are particularly vulnerable to HIV infection because their work involves working closely with the body fluids of their patients.
One significant source of HIV exposures for health care workers is accidental needlesticks. The number of accidental needlesticks is estimated to be more than one million per year.
Of these, roughly 2% are contaminated by HIV. To make matters worse, about 50% of HIV needlesticks go unreported. The significance of this problem is borne out by the fact that 80% of HIV exposures to health care workers are caused by needlesticks. Of these needlesticks, one in 200 results in an HIV infection. The CDC also estimates that 12,000 health care workers in the United States will become infected with HPV each year. Over 80% of those HPV infections acquired occupationally by health care workers will be as a result of needlesticks or other sharp instruments. Of those infected, over 200 will die. Clearly, there is a vital need for reducing the occurrence of this type of accident.
Studies reveal that more that 75% of needlesticks occur after use of the needle, in preparation for, or during disposal. Yet despite special precautions such as the use of containers for needles to be discarded and educational programs for health workers, the incidence of needlesticks has not been significantly reduced. Many experts predict that this situation will not change until needles and catheters of safer design are introduced.
Typical catheter designs for intravenous applications require that an introducing needle be used to create an opening in a vein into which the catheter can be inserted. The disadvantage of this approach is that body fluids can discharge from the opening while the needle is being withdrawn and the catheter inserted, thus risking exposure to the health care worker. Furthermore, neither the needle or catheter contains a means of protecting the worker from a needlestick.
Attempts have been made to provide a needle which can be withdrawn into a protective shield. A typical example of this type of apparatus is the PROTECTIV.TM. catheter marketed by Critikon, Inc. This device has an introducing needle which includes a protective guard for preventing contact with the needle during and after use. A catheter is attached to the needle, the needle is used to provide an introducing opening within the vein of a patient, and the catheter is inserted into this opening by sliding it off the needle as the needle is withdrawn into the protective guard. The needle is then removed from the catheter and discarded. However to complete the procedure, such devices, including the PROTECTIV.TM. design, requires that the user then attach the catheter to the intravenous tubing. During this attachment, the user is vulnerable to exposure to the patient's blood.
In the case of hemodialysis, this potential for the exposure discourages the use of catheters of this type. Instead, needles that are attached directly to intravenous tubing are preferably used. For hemodialysis patients, doctors must often perform surgery upon the patient to create a fistula. A fistula is a large, highly accessible vein, built from connecting one of the patient's veins with an artery, and designed to better accommodate numerous intravenous injections or withdrawals. Nevertheless, the introduction of the needle into the dialysis fistula risks causing significant local trauma of several varieties. Whenever a needle is inserted in the fistula, the potential for trauma to the fistula tissue exists. Further, when a needle is left in place during the hemodialysis procedure, it presents potential trauma since it may be moved to the point that it impacts or even penetrates the opposite wall of the fistula, thus leading to infiltration and bleeding. Furthermore, the removal of the dialysis needle is accompanied by applying pressure to the exit site, which usually traumatizes the inner surface of the fistula, resulting in a tendency for scarring of the fistula.
The repetitive traumatization of dialysis fistulas often leads to failure of the fistula, which is the primary cause of hospitalization for patients with End Stage Renal Disease. The use of catheters for hemodialysis offers significant advantage over metal needles. Since the catheter can be manufactured from a flexible, non-traumatizing material such as Teflon, the only trauma to the fistula is limited to the initial insertion of the introduction needle.
A device which allows placement of an intravenous tubing-connected catheter inside the vein without the need to remove the introducing needle, while allowing secure enclosure of the needle so as to prevent subsequent needlesticks is not disclosed in the prior art.